YIG Magnonics. Abdelmadjid Anane. Unité Mixte de Physique CNRS/Thales, Palaiseau et Université de Paris-Sud, Orsay, France.

Transcription

1 YIG Magnonics Abdelmadjid Anane Unité Mixte de Physique CNRS/Thales, Palaiseau et Université de Paris-Sud, Orsay, France.

2 2 / Spin based computation CMOS is one of the greatest achievement in human history buffer Non volatile logic operation Spintronic computaion Spintronic computaion CMOS interface underlayer Spintronics computational schemes Spin-FET (Datta & Das transistor) Pure spin current logique Domain wall logic, Nanomagnet logic Neuromorphic computaion (spintronic synapses) Magnon electronics

3 3 / Spin based computation CMOS is one of the greatest achievement in human history buffer Non volatile logic operation Spintronic computaion Spintronic computaion CMOS interface underlayer Spintronics computational schemes A. Khitun et al. J. of Physics D (2010) Magnon electronics (spin waves) Other applications include rf electronics APL 87, Kaiserslautern

4 Onde de spin dans les materiaux ferromagnétiques Une onde de spin est une excitation collective des spin Magnons Lee K S and Kim S K 2008 J. Appl. Phys V G ~ 10 5 m/s ~ nm La relation de dispersion dépends des caractéristiques magnétiques du matériau et de sa géométrie et du champ appliqué. L onde de spin est le vecteur d information le moins couteux en énergie Condensat de Bose Einstein

5 Micromagnetisme des ondes de spin Excitation local et propagation G est une constante du matériaux qui décrit la dissipation Pour le Py : = 0.01 et la longueur d atténuation est ~ 10 µm

6 Relations de dispersion

7 Traitement de l information avec les spin wave (Beyond CMOS) Réalisation de portes logique sur le principe de l interféromètre de Mach Zehnder miniature NOT gate OR gate AND gate L information est encodée par modulation de la phase de la SW

8 Magnetic field

9 Calcul parallel à base d interférence de SW Magnetic Cellular Nonlinear Network nce d ondes de spin

10 Applications analogiques des SW : un peu d histoire Sphère de YIG (Y 3 Fe 5 O 12 ), FMR Q 0 = Accordable de GHz

11 Ce que peut apporter l électronique de Spin

12 Filtres à base de SW

13 Filtres actifs est amplification / atténuation de SW I > 0 dm dt injec. H eff Utiliser le couple de transfert de spin pour Amplifier l amplitude des SW sous le contact ou Atténuer l amplitude des SW sous le contact dm dt Heff dm dt injec I < 0. m dm dt

14 Quelques réalisations experimentales

15 15 / Magnonics Magnonics at the nanoscale Challenge : how to couple to a spin wave with a SCALABLE scheme? It depends on the medium material If it is a metal (permalloy or Heusler alloy) STT for excitation and TMR for detection If it is a magnetic insulator SHE for excitation and ISHE for detection

16 16 / Spin Hall effect Electron diffusion with spin orbit interaction Factor of merit : spin Hall angle metal Au < 1% Pt 5% -W 30%

17 17 / Spin Hall effect and inverse spin Hall effect SHE : convert charge current to spin current ISHE convert spin current to charge current Factor of merit : spin Hall angle metal Au < 1% Pt 5% -W 30%

18 18 / YIG is the best medium for magnonics α YIG x YIG thikness

19 19 Direct SHE: damping compensation FMR while passing a large dc curent in the Pt layer

20 YIG magnonics Pure spin current magnonics requires : Direct & Inverse spin Hall Effect Large SOC metal V ISHE J c YIG (insulator) J s spin transparent interface J s Ultrathin YIG films with low damping Energy efficiency, Compatibility with standard micro fabrication, scalability of the technology MMM, Denver, November

21 Micromagnetisme des ondes de spin Excitation local et propagation buffer Spintronic computaion Spintronic computaion CMOS interface underlayer G est une constante du matériaux qui décrit la dissipation Pour le Py : = 0.01 et la longueur d atténuation est ~ 10 µm Pour le YIG : = et la longueur d atténuation est ~ 1mm

22 Pulsed laser deposition (PLD) 4 PLD deposition chambers : Manganites ZnO BiFeO 3 SrTiO 3 LaAlO 3 BaTiO 3 YBCO and many hightc SC.. YIG Olivier d ALLIVY KELLY, CNRS/THALES MMM, Denver, November

23 PLD growth PLD parameters Laser Target Substrate Laser Pulses repetition rate Nd:YAG 355nm 2.5 Hz Substrate GGG (111) Target-substrate distance 44 mm O 2 pressure 2.5 x 10-1 mbar Temperature 650 C A part from the laser there is no significant differences from the conditions used in Colorado State University by M. Wu and coll. Olivier d ALLIVY KELLY, CNRS/THALES MMM, Denver, November

24 RHEED YIG(20nm)/GGG (111) 24 / 24 Room Temperature. Room temperature. YIG(20nm)//GGG(111) Rotation( ) Po 2 (mbar) ~.10-7 ~.10-7 T( C) RT RT

25 RHEED YIG(20nm)/GGG 25 / 25 Substrate :(1) YIG :(2) YIG:(3) YIG(20nm)//GGG(111) AL4539 (1) (2) (3) Rotation( ) Po 2 (mbar) , , T( C) RT

26 26 Characterization : X-ray diffraction No parasitic phases Lattice parameter:

27 27 Characterization : X-ray diffraction No parasitic phases 20 nm 7 nm 4 nm degree

28 28 Characterization : AFM topography RMS roughness 0.3 nm on 1µm 2 4 nm 7 nm 20 nm R q = 0.3 nm R q = 0.3 nm R q = 0.1 nm R q = 0.5 nm R q = 0.5 nm R q = 0.2 nm

29 29 Characterization : SQUID magnetometry Ultra soft nanometer-thick YIG 10 nm T= 300K

30 30 Characterization : SQUID magnetometry Ultra soft nanometer-thick YIG Ms bulk YIG : 1750 G nm 7 nm nm nm Magnetic Field (Oe)

31 31 Characterization : Ferromagnetic resonance Narrow FMR linewidth

32 32 Characterization : Ferromagnetic resonance Narrow FMR linewidth ;

33 33 Characterization : Ferromagnetic resonance Spin mixing conductance Pt/YIG 20 nm Surface preparation before Pt deposition : Ar/O2 plasma /,/.. YIG.,.

34 34 Characterization : Ferromagnetic resonance Origin of of ΔH 0

35 35 YIG nanostructures etching rate 20 nm YIG on GGG SIMS detection Ar Etch conditions : Angle : 30 deg. Beam intensity : 0.50 ma/ cm 2 Acceleration voltage: 350 V

36 36 Toward nanostructures Extended Film Nanodisk

37 37 Toward nanostructures Extended Film Nanodisk Samples (300,500,700 nm)

38 38 Toward nanostructures Extended Film Nanodisk Samples (300,500,700 nm) MRFM Measurement

39 39 Ferromagnetic resonance on YIG nanodisks Extended Film Nanodisk

40 40 Ferromagnetic resonance on YIG nanodisks

41 41 Local FMR on nanodisks n=0 n=1 n=0 n=1 n=2 - discrete MRFM-spectra observed for YIG and YIG/Pt nanodiscs

42 42 ISHE measurements : Experimental results Experimental setup z x y 13 nm A. V. Chumak et al., Applied Physics Letters 100, (2012)

43 43 ISHE measurements : Experimental results z x y

44 44 ISHE measurements : Experimental results Thickness dependence of ISHE Coherent behaviour with: Y. Kajiwara et al., Nature 464, 262 (2010)

45 45 ISHE measurements : Experimental results Thickness dependence of ISHE ΔH=4.6 Oe ΔH=13 Oe ΔH=19 Oe Coherent behaviour with: Y. Kajiwara et al., Nature 464, 262 (2010)

46 Conclusion Detection of pure spin current by ISHE on 0.5nm Pd/YIG No induced magnetism in Pd/YIG Results that support SMR theory Todo list Damping compensation on nanodisks Measurements of group velocity

47 Thanks to O. d Allivy Kelly, V. Cros, P. Bortolotti and A. Fert R. Bernard, E. Jacquet and A. H. Molperces. In collaboration with : J. Ben Youssef Université de Bretagne Occidentale, LMB-CNRS, Brest, France. F. Wilhelm and A. Rogalev ID12 Beamline, (ESRF), Grenoble, France. M. Muñoz Instituto de Microelectronica de Madrid, Madrid, Spain. C. Hahn, G. de Loubens, V. Naletov, M. Viret and O. Klein CEA SPEC, Saclay France.